A sign equates mask wearing with caring for neighbors in downtown Portland on Tuesday Dec. 8, 2020. Credit: Troy R. Bennett / BDN

The World Health Organization is keeping an eye on two new strains of COVID-19 that have popped up around the world.

WHO scientists are looking into the BA.4 and BA.5 strains, subvariants of omicron, because of their “additional mutations that need to be further studied to understand their impact on immune escape potential,” the organization said Monday.

Last week, the UK Health Security Agency said BA.4 had been traced in South Africa, Scotland, England, Botswana and Denmark between Jan. 10 to March 30. All BA.5 cases have been reported in South Africa; of those, all were in people between the ages of 30 and 50 who were fully vaccinated and said they were experiencing only mild symptoms.

But the WHO said only a “few dozen” cases have been registered into the global database so far.

The new strains come as cases are on the rise in the U.S., particularly the BA.2 variant, even as vaccines are keeping people out of hospitals and morgues.